The Moment
The Moment was a sentient weapon, which the Doctor aimed to use to end the Last Great Time War. (TV: The End of Time, TV: The Day of the Doctor)
The Tenth Doctor claimed that the Eighth Doctor created the Moment from a modified Key of Rassilon and De-mat Gun during the War. (COMIC: The Forgotten, Don't Step on the Grass) In the Day of the Doctor, it is revealed he stole the weapon from the Time Lords.
The Doctor later used it to end the war, time-locking it in the process. (COMIC: Don't Step on the Grass) When the Doctor used the Moment, he destroyed Gallifrey, the Daleks, and the Time Lords. (COMIC: Sky Jacks)
The Moment's sentience prevented the Doctor from destroying Gallifrey, he instead froze it in a paralel universe. (TV: The Day of the Doctor)
The Ninth Doctor later stated that all the combatants of the Time War had burned and been "wiped out in one second". (TV: Dalek)
